It might be important to distinguish between 2 issues:
Does hypoxia (further) promote tumor growth? It looks like the answer to this has been commonly thought to be 'yes', but that that may be wrong and/or too simplistic. This seems to me to be what the passages you quote are talking about.
Is hypoxia more prevalent in larger/more progressed tumors than in smaller ones? This is what is at issue with vin..'s bavi bashing.
An interesting read (at least to my untrained eye) is this:
Which describes hypoxia in very small <1mm tumors and speculates about the relevance of micrometasteses to overall survival. Maybe this is where bavi is able to make a difference.
And, I suggest with equal qualifications: Mr. Whistler, perhaps that portrait of your mother would make her look better if she were holding a cute furry kitten and smiling.